Renal functional reserve in healthy elderly subjects.

The increase in GFR after an amino acid (AA) load, the so-called renal functional reserve, is impaired in the aged rat. Whether the renal functional reserve predicts the progression of renal disease in humans is controversial, but it is possible that age-related alterations of renal hemodynamics are relevant for the evolution of renal disease in the elderly. We compared renal hemodynamics before and after an AA infusion in 15 healthy normotensive subjects of young age (seven women, eight men; median age, 26 yr; range, 23 to 32) and in 10 subjects of old age (six women, four men; median age, 70 yr; range, 61 to 82) on normal dietary protein intake. Baseline GFR and effective RPF were measured after 12 h of fasting by the inulin (Cin) and para-aminohippurate (Cpah) steady-state infusion techniques. The renal functional reserve was examined after an overnight AA infusion (7% solution; 83 mL/h). Median basal Cin and Cpah were significantly lower (P < 0.01) in the elderly (102 and 339 mL/min per 1.73 m2) than in the young subjects (122 and 647 mL/min per 1.73 m2), but virtually all GFR values of the elderly were still within the normal range. Median Cin upon infusion of AA was 118 mL/min per 1.73 m2 (range, 98 to 137) in the elderly and 146 (range, 120 to 171) in the young, respectively. Corresponding values of Cpah were 349 mL/min per 1.73 m2 in the elderly versus 689 mL/min per 1.73 m2 in the young. Cin increased significantly (P < 0.01) after the AA load in both young and elderly subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

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Effect of ‘Autonomic Blockade’ on Cardiac β-Adrenergic Chronotropic Responsiveness in Healthy Young, Healthy Elderly and Endurance-Trained Elderly Subjects

Clinical Science ◽

10.1042/cs0870297 ◽

1994 ◽

Vol 87 (3) ◽

pp. 297-302 ◽

Cited By ~ 15

Author(s):

G. A. Ford ◽

O. F. W. James

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Geometric Mean ◽

Cardiovascular Responses ◽

The Elderly ◽

Elderly Subjects ◽

Healthy Elderly ◽

Age Related ◽

Autonomic Blockade ◽

Young Subjects

1. Cardiac chronotropic responses to isoprenaline are reduced with ageing in man. It is unclear whether this is due to reduced cardiac β-adrenergic sensitivity or to age-associated differences in reflex cardiovascular responses to the vasodilatory effects of isoprenaline. Age-associated changes in physical activity are also reported to influence β-adrenergic sensitivity. 2. The aim of the present study was to determine the contribution of alterations in reflex changes in parasympathetic and sympathetic influences and physical fitness to the age-associated reduction in cardiac chronotropic responses to β-adrenergic agonists. 3. The effect of ‘autonomic blockade’ with atropine (40 μg/kg intravenously) and clonidine (4 μg/kg intravenously) on blood pressure, heart rate and chronotropic responses to intravenous bolus isoprenaline doses was determined in eight healthy young (mean age 21 years), nine healthy elderly (72 years) and 10 endurance-trained elderly (69 years) subjects. 4. Elderly subjects had a reduced increase in heart rate after atropine (young, 49 ± 9 beats/min; elderly, 36 ± 5 beats/min; endurance-trained elderly, 34 ± 12 beats/min; P < 0.01) and did not demonstrate the transient increase in systolic blood pressure after clonidine observed in young subjects (young, 11 ± 10 mmHg; elderly, −12 ± 16 mmHg; endurance-trained elderly, −18 ± 11 mmHg; P < 0.01). 5. Cardiac chronotropic sensitivity to isoprenaline after ‘autonomic blockade’ increased in the young but decreased in the elderly subjects. The isoprenaline dose that increased heart rate by 25 beats/min before and after autonomic blockade' was: young, before 1.6 μg, after 2.8 μg, P < 0.01 (geometric mean, paired test); elderly, before 6.9 μg, after 3.6 μg, P < 0.05; endurance-trained elderly, before 5.9 μg, after 4.0 μg, P < 0.05. Cardiac chronotropic sensitivity to isoprenaline was significantly reduced in elderly compared with young subjects before (P < 0.01) but was similar after (P = 0.09) ‘autonomic blockade’. Chronotropic sensitivity did not differ between healthy and endurance-trained elderly subjects before or after ‘autonomic blockade’. 6. The age-associated reduction in cardiac chronotropic responses to bolus isoprenaline is primarily due to an age-related reduction in the influence of reflex cardiovascular responses on heart rate and not to an age-related reduction in cardiac β-adrenergic sensitivity. Endurance training is not associated with altered β-adrenergic chronotropic sensitivity in the elderly. The transient pressor response to intravenously administered clonidine may be lost in ageing man.

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Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

Nutrients ◽

10.3390/nu13072235 ◽

2021 ◽

Vol 13 (7) ◽

pp. 2235

Author(s):

Alyann Otrante ◽

Amal Trigui ◽

Roua Walha ◽

Hicham Berrougui ◽

Tamas Fulop ◽

...

Keyword(s):

Olive Oil ◽

Virgin Olive Oil ◽

Density Lipoprotein ◽

Extra Virgin Olive Oil ◽

The Elderly ◽

High Density ◽

Lipoprotein Cholesterol ◽

Elderly Subjects ◽

Age Related ◽

Young Subjects

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((3H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = −0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.

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Decreased Neutrophil Cyclic AMP Response to Isoprenaline Stimulation in the Elderly

Clinical Science ◽

10.1042/cs0650155 ◽

1983 ◽

Vol 65 (2) ◽

pp. 155-157 ◽

Cited By ~ 13

Author(s):

T. G. Cotter ◽

K. O'Malley

Keyword(s):

Monoclonal Antibodies ◽

Cyclic Amp ◽

The Elderly ◽

Population Heterogeneity ◽

Elderly Subjects ◽

Age Related ◽

Significant Difference ◽

Young Subjects ◽

Drug Free

1. Neutrophils from drug-free elderly subjects produced approximately 50% less cyclic AMP in response to isoprenaline than did neutrophils from young subjects. A significant difference in basal cyclic AMP levels was also evident (elderly 2.8 ± 0.37; young 4.9 ± 0.36 pmol of cAMP/107 cells; P < 0.05). 2. With a range of anti-neutrophil monoclonal antibodies no evidence of age-related neutrophil population heterogeneity was found. 3. These findings indicate that the age-related decline in β-adrenoceptor responsiveness is not due to changes in the neutrophil population. 4. The present results support the hypothesis that there is a generalized decline in β-adrenoceptor-mediated responsiveness in the elderly.

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The influence of dynamic visual environments on postural sway in the elderly

Journal of Vestibular Research ◽

10.3233/ves-1999-9307 ◽

1999 ◽

Vol 9 (3) ◽

pp. 197-205

Author(s):

L.L. Borger ◽

S.L. Whitney ◽

M.S. Redfern ◽

J.M. Furman

Keyword(s):

Visual Information ◽

Postural Sway ◽

Center Of Pressure ◽

Age Groups ◽

The Elderly ◽

Visual Scene ◽

Elderly Subjects ◽

Mean Velocity ◽

Healthy Elderly ◽

Young Subjects

Postural sway during stance has been found to be sensitive to moving visual scenes in young adults, children, and those with vestibular disease. The effect of visual environments on balance in elderly individuals is relatively unknown. The purpose of this study was to compare postural sway responses of healthy elderly to those of young subjects when both groups were exposed to a moving visual scene. Peak to peak, root mean squared, and mean velocity of the center of pressure were analyzed under conditions combining four moving scene amplitudes ( 2 . 5 ∘ , 5 ∘ , 7 . 5 ∘ , 10 ∘ ) and two frequencies of scene movement (0.1 Hz, 0.25 Hz). Each visual condition was tested with a fixed floor and sway referenced platform. Results showed that elderly subjects swayed more than younger subjects when experiencing a moving visual scene under all conditions. The elderly were affected more than the young by sway referencing the platform. The differences between the two age groups were greater at increased amplitudes of scene movement. These results suggest that elderly are more influenced by dynamic visual information for balance than the young, particularly when cues from the ankles are altered.

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Age-related changes in multifinger synergies in accurate moment of force production tasks

Journal of Applied Physiology ◽

10.1152/japplphysiol.00966.2006 ◽

2007 ◽

Vol 102 (4) ◽

pp. 1490-1501 ◽

Cited By ~ 57

Author(s):

Halla Olafsdottir ◽

Wei Zhang ◽

Vladimir M. Zatsiorsky ◽

Mark L. Latash

Keyword(s):

Hand Function ◽

The Elderly ◽

Time Profile ◽

Uncontrolled Manifold ◽

Elderly Subjects ◽

Total Force ◽

Dominant Hand ◽

Total Moment ◽

Age Related ◽

Young Subjects

The purpose of this investigation was to document and quantify age-related differences in the coordination of fingers during a task that required production of an accurate time profile of the total moment of force by the four fingers of a hand. We hypothesized that elderly subjects would show a decreased ability to stabilize a time profile of the total moment of force, leading to larger indexes of moment variability compared with young subjects. The subjects followed a trapezoidal template on a computer screen by producing a time profile of the total moment of force while pressing down on force sensors with the four fingers of the right (dominant) hand. To quantify synergies, we used the framework of the uncontrolled manifold hypothesis. The elderly subjects produced larger total force, larger variance of both total force and total moment of force, and larger involvement of fingers that produced moment of force against the required moment direction (antagonist moment). This was particularly prominent during supination efforts. Young subjects showed covariation of commands to fingers across trials that stabilized the moment of total force (moment-stabilizing synergy), while elderly subjects failed to do so. Both subject groups showed similar indexes of covariation of commands to the fingers that stabilized the time profile of the total force. The lack of moment-stabilizing synergies may be causally related to the documented impairment of hand function with age.

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Arginine behaviour after arginine or citrulline administration in older subjects

British Journal Of Nutrition ◽

10.1017/s0007114515004638 ◽

2015 ◽

Vol 115 (3) ◽

pp. 399-404 ◽

Cited By ~ 20

Author(s):

C. Moinard ◽

J. Maccario ◽

S. Walrand ◽

V. Lasserre ◽

J. Marc ◽

...

Keyword(s):

Plasma Concentrations ◽

The Elderly ◽

Volume Of Distribution ◽

Elderly Subjects ◽

Healthy Elderly ◽

Age Related ◽

Loading Tests ◽

Kinetics Of ◽

Healthy Elderly Subjects

AbstractArginine (ARG) and its precursor citrulline (CIT) are popular dietary supplements, especially for the elderly. However, age-related reductions in lean body mass and alterations in organ functions could change their bioavailability. Pharmacokinetics and tolerance to amino acid (AA) loads are poorly documented in elderly subjects. The objective here was to characterise the plasma kinetics of CIT and ARG in a single-dosing study design. Eight fasting elderly men underwent two separate isomolar oral loading tests (10 g of CIT or 9·94 g of ARG). Blood was withdrawn over an 8-h period to measure plasma AA concentrations. Only CIT, ornithine and ARG plasma concentrations were changed. Volume of distribution was not dependent on AA administered. Conversely, parameters related to ARG kinetics were strongly dependent on AA administered: after ARG load, elimination was higher (ARG>CIT; P=0·041) and admission period+time at peak concentration was lower (ARG<CIT; P=0·033), and the combination of both phenomena results in a marked increase in ARG availability when CIT was administered (ARG<CIT; P=0·033) compared with ARG administration itself. In conclusion, a single CIT administration in the elderly is safe and well tolerated, and CIT proves to be a better in vivo ARG precursor than ARG itself in healthy elderly subjects.

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Effect of Age on Vascular α-Adrenoceptor Responsiveness in Man

Clinical Science ◽

10.1042/cs063305s ◽

1982 ◽

Vol 63 (s8) ◽

pp. 305s-308s ◽

Cited By ~ 5

Author(s):

Henry L. Elliott ◽

David J. Sumner ◽

Kathleen McLean ◽

Peter C. Rubin ◽

John L. Reid

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Systolic Pressure ◽

The Elderly ◽

Elderly Subjects ◽

Comparable Amount ◽

Healthy Elderly ◽

Age Related ◽

Significant Difference ◽

Mean Heart Rate

1. The responsiveness of α-receptors was compared in six young and six healthy elderly subjects by evaluating the haemodynamic effects of the a, antagonist prazosin and the pressor responses to the a, agonist phenylephrine. 2. Oral prazosin (1 mg) lowered erect (but not supine) blood pressure in both groups by a comparable amount: in young and old groups the respective maximal falls in systolic pressure were 19.5 ± 15.7 and 29.3 ± 11.4 mmHg (mean ± sd) and for diastolic pressure the maximal falls were 13 ± 13.3 and 18 ± 11.1 mmHg. 3. This similar fall in blood pressure occurred in association with a significantly different heart rate response: in the young group mean heart rate increased to 103 beats/min but there was no corresponding increase in the elderly group, which had a mean heart rate of 80 beats/min. 4. Log dose-response curves were derived from incremental intravenous infusions of phenylephrine, and the doses required to raise mean arterial pressure by 20 mmHg (PD20) were compared: the mean PD20 was significantly different in the two groups: 2.5 ± 1.6 in the young compared with 4.6 ± 2.3 μg min−1 kg−1 in the elderly, consistent with reduced pressor responsiveness in the elderly. 5. No significant difference in PD20 was apparent when pressor responsiveness was determined after prazosin, but the elderly required a significantly smaller increase in phenylephrine dosage to overcome prazosin's α-receptor-blocking effects. 6. Although there is no evidence of an age-related increase in the sensitivity of α-adrenoceptor-mediated vasoconstriction, the results are not inconsistent with an age-related reduction in α-adrenoceptor responsiveness.

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SonoelastographÄ±c assessment of the age-related changes of the Achilles tendon

Medical Ultrasonography ◽

10.11152/mu.2013.2066.171.ayt ◽

2015 ◽

Vol 17 (1) ◽

pp. 58 ◽

Cited By ~ 28

Author(s):

Aynur Turan ◽

Mehmet Akif Teber ◽

Zeynep Ilerisoy Yakut ◽

Havva Akmaz Unlu ◽

Baki Hekimoglu

Keyword(s):

The Elderly ◽

The Body ◽

Elderly Subjects ◽

Reference Tissue ◽

Traumatic Injuries ◽

Age Related ◽

High Prevalence ◽

History Of ◽

Radiologic Investigation ◽

Young Subjects

Aims: Tendons are crucial for optimal muscle force transfer and subject to changes with aging which may impair func- tional ability of elderly individuals. Achilles is the largest and the strongest tendon in the body; therefore it is an excellent site for the radiologic investigation of aging of tendons. Sonoelastography (SE) is a new ultrasound-based imaging technique that provides information on elastic properties and stiffness of tissues. The aim of our study was to investigate the age-related alterations in Achilles tendons using SE. Material and methods: Forty five geriatric (age≥ 65 years) and 42 young (age 18-40 years) healthy consecutive subjects were enrolled. Subjects with known history of metabolic or endocrine diseases, sports or traumatic injuries, peripheral vascular disorders were excluded. Both Achilles tendons were scanned with a real-time SE probe at a frequency of 6–15 MHz. Strains of Achilles tendons’ proximal, middle and distal parts were assessed semi-quantitatively with comparing a reference tissue. Results: Both SE methods -color coded evaluation and strain measurement- showed a re- markably stiffer tendon in the elderly subjects compared to young subjects in all thirds of Achilles tendons. In young subjects 84.9 % tendon thirds were blue, and 15.1% were green whereas, in elders 93.7% were blue and 6.3% were green (p=0.024). There was a significant correlation between age and stiffness of tendons assessed with strain indices. Conclusion: Our result showed increased tendon stiffness in elderly subjects which might be responsible for the high prevalence of Achilles tendi- nopathies observed in elderly subjects.

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Hypothalamus-Pituitary-Adrenal Hyperactivity in Human Aging Is Partially Refractory to Stimulation by Mineralocorticoid Receptor Blockade

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2005-0105 ◽

2005 ◽

Vol 90 (10) ◽

pp. 5656-5662 ◽

Cited By ~ 39

Author(s):

Roberta Giordano ◽

Mario Bo ◽

Micaela Pellegrino ◽

Marco Vezzari ◽

Matteo Baldi ◽

...

Keyword(s):

Hpa Axis ◽

Mineralocorticoid Receptor ◽

Elderly Subjects ◽

Cortisol Secretion ◽

Mineralocorticoid Receptors ◽

Placebo Administration ◽

Healthy Elderly ◽

Age Related ◽

Young Subjects ◽

Mineralocorticoid Antagonists

Context: The hypothalamus-pituitary-adrenal (HPA) axis is mainly regulated by CRH, arginine vasopressin, and glucocorticoid feedback. Hippocampal mineralocorticoid receptors mediate proactive glucocorticoid feedback and mineralocorticoid antagonists, accordingly, stimulate HPA axis. Age-related HPA hyperactivity reflects impaired glucocorticoid feedback at the suprapituitary level. Design: ACTH, cortisol, and dehydroepiandrosterone (DHEA) secretion were studied in eight healthy elderly (75.1 ± 3.2 yr) and eight young (25.0 ± 4.6 yr) subjects during placebo or canrenoate (CAN) administration (200 mg iv bolus followed by 200 mg infused over 4 h). Results: During placebo administration, ACTH and cortisol areas under the curve (AUCs) in elderly subjects were higher than in young subjects (P ≤ 0.01); conversely, DHEA AUCs in elderly subjects were lower than in young subjects (P = 0.002). CAN increased ACTH, cortisol, and DHEA levels in both groups. In young subjects, ACTH, cortisol, and DHEA levels at the end of CAN infusion were higher (P ≤ 0.05) than after placebo. In elderly subjects, at the end of CAN infusion, ACTH, cortisol, and DHEA levels were higher (P = 0.01) than after placebo. Under CAN, ACTH and cortisol AUCs were persistently higher (P ≤ 0.01) and DHEA AUCs lower (P = 0.006) in elderly than in young subjects. Cortisol AUCs after CAN in young subjects did not become significantly different from those in elderly subjects after placebo. Conclusions: 1) Evening-time ACTH and cortisol secretion in elderly subjects is higher than in young subjects; 2) ACTH and cortisol secretion in elderly subjects is enhanced by CAN but less than that in young subjects; and 3) DHEA hyposecretion in elderly subjects is partially restored by mineralocorticoid antagonism. Age-related variations of HPA activity may be determined by some derangement in mineralocorticoid receptors function at the hippocampal level.

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Altered Brain Mitochondrial Metabolism in Healthy Aging as Assessed by in vivo Magnetic Resonance Spectroscopy

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2009.197 ◽

2009 ◽

Vol 30 (1) ◽

pp. 211-221 ◽

Cited By ~ 147

Author(s):

Fawzi Boumezbeur ◽

Graeme F Mason ◽

Robin A de Graaf ◽

Kevin L Behar ◽

Gary W Cline ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Brain Function ◽

Healthy Aging ◽

Mitochondrial Metabolism ◽

Elderly Subjects ◽

Resonance Spectroscopy ◽

Healthy Elderly ◽

Age Related ◽

Young Subjects

A decline in brain function is a characteristic feature of healthy aging; however, little is known about the biologic basis of this phenomenon. To determine whether there are alterations in brain mitochondrial metabolism associated with healthy aging, we combined 13C/1H magnetic resonance spectroscopy with infusions of [1-13C]glucose and [2-13C]acetate to quantitatively characterize rates of neuronal and astroglial tricarboxylic acid cycles, as well as neuroglial glutamate–glutamine cycling, in healthy elderly and young volunteers. Compared with young subjects, neuronal mitochondrial metabolism and glutamate–glutamine cycle flux was ∼30% lower in elderly subjects. The reduction in individual subjects correlated strongly with reductions in N-acetylaspartate and glutamate concentrations consistent with chronic reductions in brain mitochondrial function. In elderly subjects infused with [2-13C]acetate labeling of glutamine, C4 and C3 differed from that of the young subjects, indicating age-related changes in glial mitochondrial metabolism. Taken together, these studies show that healthy aging is associated with reduced neuronal mitochondrial metabolism and altered glial mitochondrial metabolism, which may in part be responsible for declines in brain function.

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